Display devices, such as rear projection television sets, may define a viewing cone fixedly positioned in a predetermined position by the manufacturer. Accordingly, especially in television sets having a high gain, a viewer that is not positioned with their eyes at the display screen's optical axis or within the viewing cone may see a much dimmer image than a viewer having their eyes positioned at the display screen's optical axis and within the viewing cone. A standing viewer, therefore, may see a much dimmer image than a seated viewer. The optical axis of the display device may be adjusted by physically adjusting the position of the entire display device, such as propping blocks under the front of the television set to raise the position of the display screen's optical axis and viewing cone. Such a method may be cumbersome, dangerous, and unaesthetic. Accordingly, it may be desirable to provide a viewing cone adjustment system that may allow adjustment of the viewing cone by a viewer, without moving the entire display device, to enhance the viewing experience.